1. Field of the Invention
This invention relates to a line start/end post or corner post of a fence.
2. Description of the Related Art
Corner fence posts are known, for example, from document U.S. Pat. No. 2,107,589 in which a wooden corner post is propped by a strengthening element comprising a metal section, a tension wire passing around the corner post, both extremities of which are looped through the eye of a threaded bolt. This tension wire is very rigid because, with the extremities thereof simply folded over, it resists the tension imparted by the threaded bolt.
Document U.S. Pat. No. 2,147,496 describes a notched metal corner picket and a strengthening element comprising another notched picket and an articulated unit having at the extremities thereof metal triangles cooperating with the notches of the pickets.
These documents describe particularly well-known elements that are difficult to implement as they require complex tools.
A “high tensile” fence is a hard-steel wire- or mesh-based fence tensioned to at least 130 to 150 kg for wire most commonly having a diameter of 2.5 mm or less.
Unlike mild-steel mesh or wire fences, which cannot be highly tensioned without the wire quickly beginning to deform irreversibly, a high-tensile fence must be made of hard-steel wire or mesh having a high carbon content and/or a high elastic limit. Such wire is often sold under the trade name Hi-Tensile or High-Tensile. It is usually in the form of 25 kg/600-650 m coils to be placed by the installer on an uncoiler of the diameter of the coil. An example of this wire is Securgal 25 (registered trademark) promoted by Lacmé in its commercial documentation for many years.
High-tensile fences are described in the documents “High-tensile Wire Fencing” from the Northeast Regional Agricultural Engineering Service, 1987, and “How to Build Fences with USS Max-Ten 200 High-tensile Fence Wire” from United States Steel, 1980. These fences are based on line pickets and corner posts. If the line pickets are made of metal, the cross-section thereof is normally T or Y shaped (the latter also being referred to as “star shaped”). T-shaped pickets are for example described in patents U.S. Pat. Nos. 1,454,649 and 5,042,591. Y-shaped pickets are for example illustrated in the documentation “The Waratah Fencing Range October 2009” from One Steel Market Mills, 2009.
One of the main problems for users wishing to erect a high-tensile fence without using the services of a specialist is the installation of the “line start/end” and “corner” posts. Indeed, line start/end posts and corner posts need to be particularly robust such as to withstand, from the outset and over time, the high mechanical tension applied to this type of fence.
A known solution involves using large-diameter wooden stakes for the line start/end posts and the corner posts. One drawback of this solution is that wooden stakes are cumbersome and heavy. Furthermore, wooden stakes are liable to decay. Moreover, these stakes, on account of the round or semi-circular section thereof, become less well anchored in the ground over time compared to metal pickets having more complex cross sections. Finally, to implement this solution, users need to master the use of several wood tools including a chainsaw and a pneumatic, thermal or hydraulic post driver to fit the wooden stakes into one another and to anchor them in the ground.
Another known solution involves using metal pickets and strengthening elements for the line start/end posts and the corner posts. Metal pickets are easier to drive into the ground, for example using a cylindrical post driver. The strengthening element may be a metal mooring or strut.
In the case of a mooring, it must be placed outside the fenced area, which reduces the space usable by the landowner, and may also cause safety problems related to the possibility of passers-by tripping over the mooring. Furthermore, moorings cannot be used for the two line start/end posts of a gateway for animal herds, since such moorings would necessarily hinder the movement of the herd passing through the gateway.
The use of struts requires specific parts manufactured in small quantities that are little-known and costly, not obvious to use, and rarely available from retail outlets. These parts also have to be transported to and then onto the installation site. In certain circumstances, such as the installation of corner posts and line start/end posts in very steep or mountainous areas, this may be an insurmountable problem. Furthermore, to assemble the strut, it is often necessary to use tightening, adjustment and/or bolting tools, which generate additional constraints in terms of weight, encumbrance and cost. Furthermore, the complexity of the work is increased by having to plan the exact number of parts required to install the corner and/or line start/end posts. Finally, struts are horizontal elements formed by a rigid rod occupying a significant amount of space.